The submarines to be acquired are commonly referred to as the Type 041 though their actual designation in China is Type 039B; their NATO designation is Yuan. Yuan class submarines have been in commission in China’s People Liberation Army Navy (PLAN) since 2006 and so far 12 have been launched with more on the way. Pakistan is currently in talks to procure eight in the coming years.

The Type 039B features advanced weaponry and an air-independent propulsion (AIP) system which allows the submarine to stay underwater for longer periods of time than a traditional diesel-electric submarine. This technology is based on Stirling engines imported from Sweden in the 1980s. This is the first time that Chinese built submarines have been chosen by a country in an open competition. Chinese submarines have been exported before to Bangladesh and Pakistan but in those cases they were direct orders.

The Chinese submarines were picked over competing German, Norwegian, South Korean, Swedish and Russian Submarines.